Hitachi, Ltd.

Masaru Nanki

Kenji Katsumata

Takanori Eda

Takumi Okamura

Toshinori Murata

Shigeru Yoneda

Satoru Takashimizu

Toshihiro Kato

Yumi Bando

Satoshi Imuro

In a digital broadcasting receiver, an identification information of the image or audio signal detected from the received digital information, and an identification information stored in an identification information memory means are compared one after another. The image/audio mute means is controlled not to output a disordered image/audio signal on the basis of the comparison result. On the basis of the comparison result, the viewer is informed by the identification information output means that resolution/quality of the received image/audio signal is changed. The identification information showing the image resolution and audio quality is inserted into digital information, and the digital information with the identification information is transmitted in a digital broadcasting transmitter.

Digital broadcasting receiver

An arrangement to automatically change between a scrambled digital data output and descrambled digital data output of a receiver by inserting a control signal conforming to a program provider's policy into a transmission signal. In a receiving side, a descrambler descrambles a channel-decoded signal, a demultiplexer demultiplexes the multiplexed signal from the descrambler into encoded video and audio data for output to a source decoder, and extracts the control information inserted in the transmitting side for output to a switch or CPU. The CPU decrypts a control signal from the control information extracted by the demultiplexer to determine whether the scrambled digital signal or descrambled digital signal is appropriate for output, and outputs a changeover control signal depending on the result of decryption. A switch selects the output of a scrambled digital signal from a stage prior to the descrambler, or a descrambled digital signal from a stage subsequent to the descrambler, depending on the changeover control signal from the CPU. Thereby, a scrambled digital signal output or descrambled digital signal output can automatically be changed over depending on a program provider's policy.

Digital broadcast transmitting and receiving system and transmitting and

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Yokohama, Japan

Masaru Nanki